<template>
    <router-view class="router-view" v-slot="{ Component }">
        <transition :name="transitionName">
            <component :is="Component" />
        </transition>
    </router-view>
</template>

<script>
import { reactive, toRefs } from "vue";
import { useRouter } from "vue-router";
export default {
    setup() {
        const router = useRouter();
        const state = reactive({
            transitionName: "slide-left",
        });
        router.beforeEach((to, from) => {
            if (to.meta.index > from.meta.index) {
                state.transitionName = "slide-left"; // 向左滑动
            } else if (to.meta.index < from.meta.index) {
                // 由次级到主级
                state.transitionName = "slide-right";
            } else {
                state.transitionName = ""; // 同级无过渡效果
            }
        });

        return {
            ...toRefs(state),
        };
    },
};
</script>

<style lang="scss">
// 不加这个样式，左右滑动特效会卡，没搞懂
.router-view {
    width: 100%;
    height: auto;
    position: absolute;
    top: 0;
    bottom: 0;
    margin: 0 auto;
    -webkit-overflow-scrolling: touch;
}

.slide-right-enter-active,
.slide-right-leave-active,
.slide-left-enter-active,
.slide-left-leave-active {
    height: 100%;
    will-change: transform;
    transition: all 500ms;
    position: absolute;
    backface-visibility: hidden;
}
.slide-right-enter {
    opacity: 0;
    transform: translate3d(-100%, 0, 0);
}
.slide-right-leave-active {
    opacity: 0;
    transform: translate3d(100%, 0, 0);
}
.slide-left-enter {
    opacity: 0;
    transform: translate3d(100%, 0, 0);
}
.slide-left-leave-active {
    opacity: 0;
    transform: translate3d(-100%, 0, 0);
}

.van-badge--fixed {
    z-index: 1000;
}
</style>
